(function () { var workerSource = document.getElementById('inlineWorker'); var blob = new Blob([workerSource.textContent]); // can I create a new script tag like this? ack... var url = window.URL.createObjectURL(blob); try { var worker = new Worker(url); } catch (e) { done(); } worker.addEventListener('message', function(e) { assert_unreached("script ran"); }, false); worker.postMessage(''); })();